FAA Aircraft Dispatcher (ADX)Flight Planning and PerformanceMedium
A dispatcher is determining maximum payload for a flight. The aircraft's Operating Empty Weight (OEW) is 95,000 pounds, Maximum Zero Fuel Weight (MZFW) is 140,000 pounds, and Maximum Takeoff Weight (MTOW) is 175,000 pounds. Fuel required for the flight is 30,000 pounds. What is the maximum payload that can be carried?
- A30,000 pounds
- B50,000 pounds
- C40,000 pounds
- D45,000 pounds
Show answer & explanationAnswer & explanation
Correct answer: D. 45,000 pounds
Maximum payload limited by MZFW is 140,000 − 95,000 = 45,000 lb. Checking MTOW: 95,000 (OEW) + 45,000 (payload) + 30,000 (fuel) = 170,000 lb, which is under the 175,000 lb MTOW limit, so MZFW is the binding constraint at 45,000 lb.
Why the other options are wrong
- A. 30,000 lb underestimates the MZFW-limited payload.
- B. 50,000 lb would exceed the MZFW limit (145,000 lb ZFW).
- C. 40,000 lb is not the calculated MZFW-based limit.
Payload Limited by MZFW
Maximum payload is the lesser of the MZFW-limited payload (MZFW − OEW) or the MTOW-limited payload (MTOW − OEW − fuel required).
- ZFW = OEW + Payload, must not exceed MZFW
- TOW = ZFW + Fuel, must not exceed MTOW
- The most restrictive limit determines maximum payload
Memory trick: 'Zero fuel first, takeoff second' — check both, use the smaller number.